David Rorvik makes clear that he could have taken the easy way and made up parts of his book announcing the birth of the world's first human clone.

If he had invented the story, Rorvik said in an interview yesterday, he wouldn't have been stuck with a plot involving an orphan-to-millionaire loner seeking to clone himself, a 16-year-old virgin orphan who provides a womb for the clone and a secret laboratory in an unidentified Asian country.

Nor, presumably, would he have been forced to record for us that Max, the 68-year-old millionaire, and Sparrow, the peasant girl, fall in love - at least to the point that Max is considering either marrying or adopting Sparrow, making the young virgin either mother or sister to the clone she bore.

A clone is an identical replica of its single parent, using the genetic information locked in a single cell, started in a laboratory and then implanted in a womb and brought to term. Max thus ran no risk of getting a daughter, nor did he have to content himself, as do other partents, with having contributed only half his child's chromosomes.

"Put yourself in this position," Rorvik, a science journalist, said. "Would you dare risk writing such a story? In effect, you're jeopardizing your entire career."

Rorvik, who book has met with widespread disbelief in the scientific community, said: "I went forward with great trepidation. But I felt it would be terribly irresponsible for me to be a witness to something like this and then say nothing about it."

Much better, Rorvik said, to take the risks and put his book before the public so that it may spark some public debate on genetic engineering.

It has sparked some debate. It also will make Rorvik a lot of money.

In the book, "In His Image, the Cloning of a Man," Rorvik explains that he refused offers of large amounts of money from the millionaire that might have tied his hands. Max did not want him to write anything about the cloning.

"Well, I didn't say I'm going to profit from this by writing a book," Rorvik replied in describing his refusal to take Max's funds.

"I couldn't predict that I would [profit] and I don't know how much money I'll make now," Rorvik said.

Pocket Books purchased paperback rights for a reported $250,000.

What about a movie? Rorvik was asked.

"Well, if someone wants to make a movie and it's handled in a responsible way," Rorvik said. He referred the question to his agent, Barbara Lowenstein, who said: "We're very close to making a deal."

Rorvik is preparing to travel on behalf of his book. He'll go to England, Australia, Japan and perhaps other countries as the foreign editions are published. J. B. Lippincott has issued a first printing of 80,000 copies and called for 20,000 more.

Rorvik emerged from hiding this week to do a series of interviews promoting his book. He explained that he had not been available earlier because "Lippincott thought it best for me to absent myself because they felt that nobody could very responsibly discuss this matter until the books were available."

He thinks that was a wise decision. He says criticism of the book by scientists who had not read it, (but who consider it wildly implausible that the technical problems involved in cloning humans have actualy been overcome) was often "pretty irresponsible."

For all that, however, Rorvik said: "I haven't felt there's been any really serious claim of challenge to my assertion that a human has been cloned."

Although no scientists have rushed to his public defense since reading the book, one columnist has, and Rorvik is delighted.

Max Lerner, in a column in the New York Post Wednesday wrote that, "At the risk of being a laughing stock for the rest of my life" he takes Rorvik seriously.

Lerner concludes that Rorvik's story is too unbelievable and too upbeat in its happy ending for the millionaire Max, Sparrow and the unnamed clone, now 15 months old, to be a ripoff. "Sometimes life imitates bad art," Lerner wrote.

The kinship with bad art is not weakened by occassional author's musings such as:

". . . I did think about it, this matter of soul perhaps. That was the one part of man you could never clone."

Rorvik has an ability to be on both sides of some questions that would do many politicians proud. "The implausibility of [the story], if anything, works in my favor," he said. He also said "there are many gaps I could have filled in with false material that most people would have just swallowed wholesale," and that would have lessened criticism of him.

"I entertain absolutely no expectation that any one scientist or layman will accept this book as proof of the events described herein," Rorvik wrote.

Yet, he said, "I think people who will carefully read my book will see that [his critics] are demonstrably wrong."

According to the book, millionaire Max telephoned Rorvik because he had read some of Rorvik's articles on genetic engineering in major magazines, and proposed that Rorvik find him a scientist willing to attempt to clone Max.

Max wanted a male heir, but hadn't found a woman with worthy genes, although, Rorvik assures us, Max had nothing against sex.

After Rorvik finds the scientist, code-named Darwin, he fulfils no further purpose, but Rorvik said, "They were stuck with me." If Max and Darwin had not let him follow the cloning progress, Rorvik said, "that would have justified my pointing the finger at them."

"I might have arrived with cameras and a surprise party of reporters," he said.

So, although Rorvik, in the book writes that he did not witness many of the crucial steps in creating Max' clone, he says he was present when Sparrow gave birth to it two weeks before Christmas in 1976.

Now, he said, he is lobbying Max to get the happy father to bring forward documentation of his feat. At present Max has no such interest, Rorvik said.

Rorvik said Max's reaction to the book was that "everytime someone cries hoax, he's delighted."